Combined agitator and conveyer mechanism



'Jan. 7, 1941. F. w. WEIGEL COMBINED AGITATOR AND CONVEYER MECHANISM Filed Aug. 19, 1939 bmamim zw. WW a Qttornegjs Patented Jan. 7, 1941 UNITED STATES COMBINED AGITATOR AND CONVEYER MECHANISM Frederick W. Weigel, Knoxville, Tenn, assignor to The V. D. Anderson Company, Cleveland, Ohio,

a corporation of Ohio Application August 19, 1939, Serial No. 291,100

6 Claims.

This invention relates to agitator-conveyers, that is, to agitators which mix material and at the same time convey it in a given direction. More particularly, it relates to continuous conveyers of the rotating type adapted to impart a rapid back and forth movement to material being conveyed, and to accomplish this with comparatively slight expediture of power.

In the prior art it has been proposed to utilize opposed sets of stirring blades in order to impart back and forth movement to material to be mixed. In such arrangements, however, it has usually been the practice to utilize fiat blades or paddles which have the disadvantage of requiring considerable power for their operation because of the resistance opposing entry of the blades into the material under treatment. The present invention, therefore, is directed to a solution of the problem of reducing the expenditure of power, and at the same time adding a conveying function to the agitating function.

According to the present invention, the agitating blades are so arranged as to provide for an overlap between the sphere of operation of one blade and the next succeeding blade and, at the same time, the parts are so constructed and arranged that they cannot become loosened during operation.

The main object of the invention is, therefore, to provide a unitary mechanism capable of performing a thorough mixing of material and, at the same time, conveying it from one point to another at a predetermined rate.

Other objects and advantages will appear from the following description when read in connection with the accompanying drawing in which:

Figure 1 is a perspective view of one form of agitator conveyor embodying the present invention;

Fig. 2 is a side elevation of the device of Fig. 1 showing a construction in which the conveying movement of the material during agitation is accomplished by providing blades of different lengths;

Fig. 3 is a side elevation of a modified form of the invention where the conveying movement is accomplished not by a difference of blade length, but by a difference in blade angularity;

Fig. l is a sectional view through a treating chamber containing an agitator-oonveyer of the type shown in Fig. l, the chamber being of the closed type; and

Fig. 5 is a view similar to Fig. 4 showing application of the invention to a treating trough of the open type.

In the drawing reference character 8 designates the shaft of an agitator-conveyer, this shaft being adapted to be mounted in suitable bearings. As shown, it rotatab-ly carried by a through shaft 9. The shaft 8 carries two sets of supporting pins, those disposed vertically as shown being designated l2, and those disposed at right angles or horizontally being designated H. These pins may be permanently secured to the shaft 8 in any suitable manner as by welding or, where the shaft 8 is solid, the shaft may be drilled and the pins passed through the drilled openings. Any equivalent fastening means are contemplated. It is to be pointed out, however, that a permanent fastening means, such as that illustrated, is desirable because it prevents the failures due to loosening of bolts, clamps, set-screws, and the like, which have for the most part characterized the structures of the prior art.

A plurality of helical blades I3 have their forward ends attached to the ends of the horizontal pins II, and their rearward ends similarly to the pins l2, as by welding. The welds are indicated at It. The blades I3 have elongations or tails i4 projecting beyond the pins i2 and the inclination and curvature of these blades is such that when they are rotated in a mass of more or less solid material, a thin edge of the blade is presented to the mass, causing the blade to cut into the mass and move through it with slight power expenditure. All of the blades it are inclined in the same direction and are so arranged that when the shaft 8 is rotated in the direction indicated by the arrow in Fig. l, the material is caused to move from left to right as indicated by the arrow K.

The shaft 8 also carries a plurality of other helical blades I5 corresponding structurally, except for length, to the blades is and each having an end attached to pins. H and it, but disposed at an angle opposed to that of the blades l3. Consequently, the inclination of the blades i5 is such as to cause travel of the material in a direction opposite to that caused by blades it, it being noted, however, that there is an overlap between the tail of each blade l3 and the forward end of an opposed blade [5. In other words, the blades are staggered circumferentially about the shaft, and the blades, which are of two types designed to produce two diiferent effects, are in alternating relation. No two blades of the same type are juxtaposed, hence the agitating or mixing function is amplified to a maximum degree. This arrangement insures that the spheres of operation of the separate blades overlap and cause a thorough and complete agitation of the entire mass without the formation of dead spots or spheres of inactivity in the mass under treatment.

As a result of the arrangement indicated in Fig. 1, rotation of the shaft 8 in a direction indicated by the arrow, will cause the blades It to move the material from left to right as indicated by arrow K, while the blades 15 will, at the same time, move it to a lesser degree from right to,

left. Consequently, material under treatment will be placed in a continuous state of agitation with particle movement from right to left and left to right, but since the blades it are longer than the blades l5 by the length of tails l4, there is a conveying action causing a resultant travel of the mass from left to right as indicated by arrow K. This difference in effect is also brought out by the difference in length of the dark arrows of Figs. 2 and 3. The rate of this travel will, of course, be determined by the speed of shaft rotation and the length of the tails it.

While the agitator-conveyer herein shown is adapted for many uses, it will find its more common use in locations where there is a lateral infeed to the chamber or trough containing the conveyor. This makes it desirable to provide some means for initiating the operative Contact between the conveyer or agitator blades and the material to be conveyed. This means may conveniently take the form indicated in the left hand end of Fig. 1, in which a continuous section of spiral l! is secured to pins IS. It imparts initial movement to material to be fed, throwing it into contact with the first blade l3, whence it is agitated and conveyed in the manner just described.

Although, as indicated, the device in question may be adapted to numerous uses, Fig. 4 gives by way of example an illustration of the conveyer mounted in a cylindrical drum or treating chamber I9 having an outer jacket 21 to provide a space 20 between the drum and the jacket for the receipt of heating or cooling medium to control the temperature and consistency of the material to be treated. In Fig. 4, the elongations or tails M on the blades l3 are evident.

As still another example of the use to which this device may be put, Fig. 5 shows it applied to an open trough 22 of U-shape formation having a jacket 23 to which a heating or cooling medium may be supplied through the pipe 24. Here, again, the opposed inclination of the two types of blades l3 and I5 is evident, and the blade tails or elongations M are indicated. It should be pointed out in connection with this agitatorconveyer that the separate blades may be mounted in such close proximity to the wall with which they cooperate as to make them function as scrapers, keeping the surface of the trough 22, for example, clear of material within the sphere of operation of the agitator.

In the example just given, it has been indicated that the difference in movements of material caused by the two types of blades is brought about by difference in blade length. This is indicated even more clearly in Fig. 2 where the spacing of the pins I la and Im is diflerent than in Fig. 1, giving a sharper angularity to the conveyer blades. In this figure, the tails or elongations are indicated I ia, parts similar to those of Fig. 1 being indicated by the same reference character as before but with the subscript a. As indicated in Fig. 2 by the dot-dash line ABC, the angularity of the blades of the two types is the same, so that if the tails Ma were omitted, the

material would be subjected to rapid agitation but without resultant forward movement.

It will be apparent to those skilled in the art that the invention may take forms other than those indicated in Fig. 2, one such modified form being indicated in Fig. 3 where the forward movement or conveying is accomplished not by a difference in blade length, but by disposing the blades of one type at a different angle than those of the other type. This difference in angularity is indicated by the dot-dash line ABC. In

this figure, the reference characters correspond to those of Fig. 1 with the subscript 1) added. Here, while the pins llb and I212 are disposed in relation as heretofore, all of the blades are of the same length, i. e., do not have any tails or elongations. However, the blades I5b are disposed at a sharper angle than the blades I3b, that is, they have a smaller pitch than the blades [3b, so that when the conveyer of Fig. 3 is rotated in the direction indicated by the arrow, the blades 13b cause a more rapid travel from left to right than do the blades 15b, which move the material from right to left. This difierence in angularity is produced by the spacing of the pins llb and 12?), it being noted that whereas in Figs. 1 and 2 the spacing of the pins is equal throughout the length of the conveyer shaft, in Fig. 3 the vertical pins are evenly spaced with respect to one another while the horizontal pins are unevenly spaced with respect to the vertical pins in front of and in back of them. In other words, as shown in Fig. 3, the distance L is always greater than the distance M. Obviously, this pin spacing and blade angularity may be varied as conditions may require, to vary the speed of agitation and the speed of conveying, or both of them together.

As recognized in the prior art, it has been s ggested to provide helical blades arranged to reduce the amount of power required to operate them. It has also been suggested to impart reciprocatory movement to material under treatment by the use of opposed sets of blades, and also to utilize movement of agitation with result ant forward travel. However, it is believed that the present concept of utilizing individual helical blades of different types arranged in alternating relation and for overlapping effects, and designed to produce combined agitation and conveying is new, .be it accomplished by difference in blade length or by diiference in angularity.

What is claimed is:

1. A combined agitator and conveyer structure comprising a casing containing a rotatable shaft; a plurality of individually mounted helical blades secured thereon in circumferentially staggered relation so that each blade extends into the sphere of action of at least one other blade, all of said blades having substantially the same radius and being movable in close proximity to the casing wall, certain of said blades being arranged to move material in one direction in said casing, and certain others of said blades being arranged to move material in the other direction in said casing at a rate diiferent from that caused by the first mentioned blades.

2. A combined agitator and conveyer structure comprising a casing having a shaft rotatably mounted therein; a plurality of helical blades of one length individually secured on said shaft in circumferentially staggered relation to one another to move material along said casing in one direction; and a plurality of other helical blades individually secured on said shaft in circumferentially staggered relation to one another in alternating relation with the first blades and of greater individual length than the first blades to move material along said casing in the other direction at a greater rate than that imparted to it by the first blades, all of said helical blades having substantially the same radius and being movable in close proximity to the casing wall.

3. A combined agitator and conveyer structure comprising a casing having a shaft rotatably mounted therein; a plurality of helical blades disposed at one angle with respect to said shaft and individually secured thereon to move material along said casing in one direction; and a plurality of other helical blades individually secured to said shaft at a different angle with respect to the shaft than said first blades, and in alternating relation with said first blades to move material along said casing in a direction opposed to, and at a rate different from, that resulting from the action of said first blades, and all of said blades having substantially the same radius and being movable in proximity to the casing wall.

4. A combined agitating and conveying mechanism comprising a casing containing a rotatable shaft; a plurality of supporting elements secured to said shaft; and a plurality of helical blades permanently secured to said elements, said blades being of two types disposed in alternating relation and arranged for overlapping effects, all of said blades having substantially the same radius and being movable in close proximity to the casing wall, the blades of one type being disposed to cause movement of material in one direction in said casing, and the blades of the other type to cause movement in the opposed direction at a rate differing from that caused by the blades of the first type.

5. A combined agitating and conveying mechanism comprising a casing containing a rotatable shaft; a plurality of supporting elements secured to said shaft; and a plurality of helical blades permanently secured to said elements, said blades being of two lengths disposed in alternating relation and arranged for overlapping effects, all of said blades of both lengths having substantially the same radius and being movable in close proximity to the casing wall, the shorter blades causing movement of material in one direction in said casing, and the longer blades causing movement of material in the opposite direction at a greater rate.

6. A combined agitating and conveying mechanism comprising a casing containing a rotatable shaft; a plurality of supporting elements secured to said shaft; and a plurality of helical blades permanently secured to said elements, said blades being of two types disposed on said shaft and arranged for overlapping effects, the blades of both types being inclined to said shaft, and those of one type having a different inclination than those of the other type, and the blades of both types having substantially the same radius and being movable in close proximity to the casing wall.

FREDERICK W. WEIGEL. 

